❗ The Problem: Why Do SMPS Voltage Spikes Happen?

Switch Mode Power Supplies (SMPS) are widely used for their efficiency, but they often introduce voltage spikes—short, sudden bursts of high voltage. These spikes usually occur when driving inductive loads like motors, relays, or solenoids, or due to poor filtering. The result? Damaged microcontrollers, erratic behavior, or total circuit failure.

🛠️ The Solution: How to Prevent Voltage Spikes

To protect your components, use these simple fixes:

• TVS Diodes (Transient Voltage Suppression): Clamp spikes to safe voltage levels.

• Flyback Diodes: Redirect back EMF from motors and relays safely.

• Snubber Circuits: Combine a resistor and capacitor to absorb switching noise and transient energy.

🔍 Practical Example: Fixing an Arduino Motor Reset

Let’s say you’re powering an Arduino motor driver with a 12V SMPS. When the motor stops, the Arduino resets. This happens due to a voltage spike from the motor’s back EMF.

Fix it with:

• A 1N5819 Schottky diode across the motor terminals (cathode to +).

• A 470µF electrolytic capacitor across the 12V supply near the Arduino.

Result: No more resets, stable performance!

🧮 Sample Calculation: Sizing a Snubber Resistor

Say your 12V relay coil draws 100mA. Here’s how to size a snubber resistor:

• Resistance:

• R=IV​=0.1A12V​=120Ω

• Power Rating:

• P=V×I=12V×0.1A=1.2W

• Use a 2W, 120Ω resistor for safe operation.

Pair it with a 100nF, 250V ceramic capacitor for effective suppression.

🛒 Product Suggestion: Made in India Components for Spike Protection

Protect your projects using high-quality, Made in India components:

🔧 Buy TVS Diodes – Made in India

🔧 Get 1N5819 Flyback Diodes – Made in India

✅ Shop now at SmartXProKits.in
Support our work and India’s innovation—buy from our Make in India site!